All right, go play in Africa (thing)

And here were the lions now, fifteen feet away, so real, so feverishly and startlingly real that you could feel the prickling fur on your hand, and your mouth was stuffed with the dusty upholstery smell of their heated pelts, and the yellow of them was in your eyes like the yellow of an exquisite French tapestry, the yellows of lions and summer grass, and the sound of the matted lion lungs exhaling on the silent noontide, and the smell of meat from the panting, dripping mouths.

The lions stood looking at George and Lydia Hadley with terrible green-yellow eyes.

"Watch out!" screamed Lydia.

The lions came running at them.

Lydia bolted and ran. Instinctively, George sprang after her. Outside, in the hall, with the door slammed he was laughing and she was crying, and they both stood appalled at the other's reaction.

Ray Bradbury's short story about a pair of children who feed their parents to the somewhat more-than-virtual pride of lions residing in their high tech playroom infatuated me as a child. Imagine, a place you could go to—in your own home—as exotic and exciting and dangerous or peaceful and contemplative as your own imagination.

It seems that the future always comes at us in ways we can't anticipate. The genre we've come to term Science or Speculative Fiction appears most often to be quaint and off-target when viewed in retrospect. 2001 came and went, for example, without even a major revival of Stanley Kubrick's landmark film, let alone a concerted effort on the part of the human race to colonize the moon and beyond.

We don't have flying cars and we aren't immortal and nobody knows why, exactly, the common cold can lay some of us lower than expectations of a profit from John Travolta'sBattlefield Earth.

Much success has been found of late in the area of flat-screen gas-plasma and liquid crystal displays (LCDs), two possible components of any real-world version of Bradbury's futuristic playroom. I walked into a high-end television showroom a couple of weeks ago and thought I was looking through a window instead of at a twenty thousand dollar flat-screen high definition TV monitor. But one of the important aspects of Bradbury's construction was its affordability. In his future, they can get it for you cheap. Four walls, a ceiling and a floor's worth of high-def LCD monitors? Well, we're talking Bill and Melinda Gates territory there. But there may be a better way.

Dirk Broer and his colleagues at Eindhoven University of Technology and Philips Research Laboratories in The Netherlands have developed what may become an essential component of the living room—or playroom—of the future: paint-on liquid crystal displays.

Liquid crystals, you'll recall, have a very useful quality: their molecules, instead of being dispersed randomly like those of most liquids, line up, like tin soldiers at attention. When a voltage is applied across the molecules their alignment changes, switching a display, for example, from light to dark.

We've seen the technology on everything from digital watches and thermometers to mobile phones, laptop computers, and— most-recently—television screens. At the present, however, the crystals are sandwiched between heavy glass plates. Production techniques are expensive and time-consuming. The size of today's LCD screens is limited.

Broer and his team, however, have managed to deposit a layer of liquid crystal on a single underlying sheet, basically painting the molecules onto the surfaces of glass and plastic. Broer predicts that fabric will be next, which probably means that not only will our wardrobes be infinitely variable, but we'll also be walking around with animated advertisements on our T-shirts, which will change as new images are downloaded from our Palms.

LCD paint is created by mixing the liquid crystal with molecules that link together into a rigid polymer when exposed to ultraviolet light. Effectively, a series of tiny boxes are built which hold the liquid. The base is coated with a thin layer of this LCD paint and squares are masked out. When ultraviolet is applied, a grid is formed. The mask is removed and a second exposure of ultraviolet (at a wavelength that doesn't penetrate the whole liquid layer) seals all the boxes over, like a lid.

The construct differs from standard LCDs, which are divided up into pixels and whose voltage is applied to electrodes on the two glass plates. LCD paint passes voltage between two points on the same plate.

The technique will certainly be applied to laptop computers, whose heavy glass screens are a major portion of their cost. Plastic screens will be cheaper, lighter, and more durable. Eventually we should see giant TV screens, digital billboards, and—no doubt—walls that will animate and change color, if not the minds of the parents who install them in the rooms of children who've read The Veldt.